The invention concerns an apparatus for simultaneously conveying and regulating the temperature of shaped parts according to the preamble to claim 1. Such apparatuses, which shall hereinafter be called temperature-regulating conveyors, are known and are particularly used to remove by conveying plastic shaped parts directly after production thereof in a press-stamping machine and simultaneously rapidly cool them down to a temperature at which their shape is stable. One example of a plastic shaped part in which this is required is a screw cap for a drinks bottle. Such caps, which may for example consist of polypropylene or polyethylene, are produced in great numbers by injection moulding and are then removed from the mould in the machine at a temperature of approximately 100° C., whereby their form is not yet stable. In order to be able to take them directly to further processing after their production, they must be cooled as quickly as possible down to the specified processing temperature. The throughput of the cooling apparatus must be thereby adapted to the high production rate of today's injection-moulding machines, which produce about 1200 caps per minute.
Prior-art temperature-regulating conveyors typically consist of a conveyor belt and of fans located thereabove that blow temperature-regulated air onto the conveyor belt. However, in order to achieve a high throughput with such an arrangement, a great length and/or width of conveying line and therefore a correspondingly great size of temperature-regulating conveyor is required.
A conventional apparatus for the conveying and simultaneous cooling of substrates for data-carrying discs such as CDs, DVDs or the like is known from DE 199 07 210 A1, wherein the substrates rest on carriers during conveying, which carriers slide on an air cushion. Conveying occurs by means of the air cushion along an open channel with a U-shaped section, in the base plate of which a plurality of diagonal air inlet openings are provided for the production of an air cushion with a horizontal stream component. In order to guide part of the cooling air flow onto the substrates, each of the carriers has a vertical and several substantially horizontal holes, which together form a distribution system, through which air in the carrier can flow out, first centrally upwards and then laterally via the substrate. This apparatus is specially designed for the requirements of DC and DVD production and is relatively expensive because of the carriers with an internal air-distribution system that are required.
U.S. Pat No. 4,418,482 discloses an apparatus for simultaneous conveying and cooling of plastic bottles after ejection from a injection-moulding machine. The bottles lie with their necks on two rollers that are parallel to one another and rotate in opposite directions to one another along a fissure between these rollers. The main part of each bottle protrudes thereby into a hollow space underneath this fissure, wherein an air stream is blown for cooling. The manner of operation of this apparatus is based on the shape of the plastic bottles and is suitable only for objects of such or of a similar shape.
DE 25 09 469 B2 relates to a pneumatic conveying system for conveying pieces of matter, whereby the conveying line is constituted by a vertically extending channel that is closed on all sides. An upwardly directed air stream is created in the channel by blowing in air via diagonal openings on one side of the channel, the open cross-section of which channel corresponding approximately to the cross-section of the conveyed matter, the conveyed matter in the channel being moved upwards by the dynamic pressure of the air stream. The apparatus serves exclusively for the conveying of the conveyed matter. Its temperature is of no interest.
Lastly, JP 2000 280 265 A shows a cooling apparatus for objects made of plastic, wherein containers circulate in a chamber that is cooled by an air stream. The objects are continuously placed in the containers as they arrive and after one cycle in the chamber they are taken out of the containers again.